The technology of dyeing in supercritical carbon dioxide fluid has significant characteristics of clean production, such as ecology, environmental protection, energy conservation and emissions reduction, and it is of great importance for changing present situation of high pollution and energy-intensive in the traditional textile printing and dyeing industry. At present, the hydrophobic synthetic fibres such as polyester can obtain a good dyeing effect with disperse dyes in supercritical carbon dioxide fluid. The technology has gradually developed from small sample studied in the laboratory to application of pilot trials, and some commercial samples or products have come onto market (referring to the publications: Pilot trials of supercritical CO2 dyeing of polyester fabric [J]. Dyeing and finishing, 2013 (10):49-53; DyeCoo Textile System B.V., Nike, Inc. announces strategic partnership to scale waterless dyeing technology. Available from: www.dyecoo.com/pdfs/press-release-nike.pdf, 2012).
However, it's much more complex and difficult to dye and fix with the hydrophilic natural fibers in supercritical carbon dioxide fluid. At present, it is generally believed that it's one of the feasible and effective ways to realize natural-fibre textiles dyeing in supercritical carbon dioxide fluid with disperse reactive dyes which are structure-optimized (referring to the publications: Dyeing of cotton fabric with a reactive disperse dye in supercritical carbon dioxide, The journal of supercritical fluids, 2012, 69: 13-20; Solubility of a reactive disperse dye in supercritical carbon dioxide, Coloration technology, 2012, 128: 127-132). One of the difficulties is how to achieve the reaction of dyes and fibres in the weak acidic medium of supercritical carbon dioxide fluid, and reduce the processing conditions while maintaining high fixation efficiency.
Therefor, the research of unit device and process about textile fixing in supercritical carbon dioxide fluid, especially for natural-fibre textiles, has very important significance and a broad market prospect as it facilitates the process of textiles anhydrous dyeing and fixing, and achieves the clean production of enterprises of textile printing and dyeing thoroughly.